1. Field of the Invention
The present invention relates to a non-contact type compact magnetic induction switch capable of being ON and OFF by a slight operating force.
2. Description of the Related Art
As for a conventional compact switch, there are available a mechanical contact type switch and a proximity switch utilizing an oscillator. However, the contact type switch has its limit in making the operating force small, and further miniaturization thereof is difficult. While, the proximity switch is complicated in its structure, and has its limit in reducing the cost.
Further, a hole effect type position sensor which combines a permanent magnet and a hole element is used as position detection means for various types of equipment. This position sensor attaches the permanent magnet to a detected body whose position is desired to be detected so that magnetic field generating portions are constituted and, at the same time, a magnetic detection portion comprising the hole element is constituted so as to be relatively displaced against these magnetic field generating portions. When the magnetic field generating portions come close to the magnetic field detection portion, the hole element of the magnetic field detection portion detects the magnetic field from the magnetic generating portions by means of the hole effect and outputs an electrical signal, thereby detecting the position of the detected body. The hole effect type position sensor which constitutes such a hole element as the magnetic field detection portion does not have a mechanical contact such as a micro switch and the like, and has the advantages of being highly reliable in operating in non-contact on the detected body and, hence, is adopted in a wide range of applications.
Since the object of the sensor is to detect the position, though a measure for improving position detection accuracy is taken, using the sensor as a compact switch is not taken into consideration. Therefore, improving the function of the sensor as the compact switch is not taken at all.
The object of the present invention is to provide an ultra compact magnetic induction switch, whose operating force is made as small as possible and whose size is made as compact as possible.
In order to achieve the above-described object, the compact magnetic induction switch comprises: a switch case; a movable member provided inside the switch case; an elastic body which is installed inside the switch case and urges an end portion of the movable member so as to protrude it outside of the switch case; a hole IC arranged adjacent to the movable member inside the case; and a magnet fixed to the movable member, wherein the magnet is constituted so as to be moved so that an output of the hole IC is put into an OFF or ON state at non-pressing time of the end portion of the movable member and the output of the hole IC is put into an ON or OFF state at pressing time of the end portion of the movable member.
Additionally, the above-described object is realized by the compact magnetic induction switch comprising: a switch case; a movable member provided on an opening of the switch case and being reciprocally movable; an elastic body which is installed inside the switch case and urges an end portion of the movable member so as to be protruded outside of the switch case; a magnet fixed to the movable member; and a hole IC for detecting change of magnetic field caused by movement of the movable member with its operating point, wherein if the magnet field applied to the operating point of the hole IC becomes above or below a threshold by movement of the movable member, output signal of the hole IC switches on/off.
In the compact magnetic induction switch of the present invention, the positioning portion which positions the hole IC at a predetermined position may be provided inside the switch case.
Alternatively, a guide portion which guides the movable member may be provided inside the switch case. A lid member which is fitted into the bottom of the switch case may be provided and an opening which derives the lead wire of the hole IC or an opening which injects a filling agent may be provided on the lid member.